[JAVA][Beginning Java 8 Games Development]

Chapter 3 ■ A Java 8 Primer: An Introduction to Java 8 Concepts and Principles
JDK compiler (program) turns your Java code into bytecode that is executed or run by a Java Runtime Engine (JRE).
This JRE, in this case it is JRE 8, is installed on your end user’s computer system. The Java compiler needs to know
where your Java code blocks begin and end, where your individual Java programming statements or instructions
begin and end within those Java code blocks, and which parts of your code are Java programming logic, and which
parts are comments to yourself, or comments (notes) to other members of your game project programming team.
Let’s start with comments, as this topic is the easiest to grasp, and you have already seen comments in your
InvinciBagel game bootstrap Java code, in Chapter 2. There are two ways to add comments into Java code: single-line,
also referred to as “in-line,” comments, which are placed after a line of Java code logic, and multiple--line, or “block,”
comments, which are placed before (or after) a line of Java code or a block of Java code (a Java code structure).
The single-line comment is usually utilized to add a comment regarding what that line of Java logic, which I like
to call a Java programming “statement,” is doing, that is, what that line of Java code is there to accomplish within your
overall code structure. Single-line comments in Java start with the double forward slash sequence. For instance, if
you wanted to comment one of the import statements in the InvinciBagel bootstrap code that you created in Chapter 2,
you would add double forward slashes after the line of code. This is what your Java code would look like once it has
been commented (see also Figure 3-1, bottom right):
import javafx.stage.Stage // This line of code imports the Stage class from JavaFX.stage package
Figure 3-1. Multiline comments ( first five lines of code, at the top) and single-line comments (last three lines of code, at
the bottom)
Next, let’s take a look at multiline comments, which are shown at the top of Figure 3-1, above the package
statement (which you will be learning about in the next section). As you can see, these Java block comments are done
differently, using a single forward slash next to an asterisk to start the comment and the reverse of that, an asterisk
next to a single forward slash, to end the multi-line comment.
As you can see in the InvinciBagel.java code editing tab in NetBeans 8.0, just as I lined up the single-line
comments to look pretty (cool) and organized, so too the Java convention in block commenting is to line up the
asterisks, with one as the beginning comment delimiter and one as the ending comment delimiter.
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